A percolation-type criticality threshold controls immune protein coating of surfaces.

When a material enters the body, it is immediately attacked by hundreds of proteins, organized into complex networks of binding interactions and reactions. How do such complex systems interact with a material, "deciding" whether to attack? We focus on the "complement" system of ∼40 blood proteins that bind microbes, nanoparticles, and medical devices, initiating inflammation. We show a sharp threshold for complement activation upon varying a fundamental material parameter, the surface density of potential complement attachment points. This sharp threshold manifests at scales spanning single nanoparticles to macroscale pathologies, shown here for diverse engineered and living materials. Computational models show these behaviors arise from a minimal subnetwork of complement, manifesting percolation-type critical transitions in the complement response. This criticality switch explains the "decision" of a complex signaling network to interact with a material, and elucidates the evolution and engineering of materials interacting with the body.

Nanocarriers' repartitioning of drugs between blood subcompartments as a mechanism of improving pharmacokinetics, safety, and efficacy.

For medical emergencies, such as acute ischemic stroke, rapid drug delivery to the target site is essential. For many small molecule drugs, this goal is unachievable due to poor solubility that prevents intravenous administration, and less obviously, by extensive partitioning to plasma proteins and red blood cells (RBCs), which greatly slows delivery to the target. Here we study these effects and how they can be solved by loading into nanoscale drug carriers. We focus on fingolimod, a small molecule drug that is FDA-approved for treatment of multiple sclerosis, which has also shown promise in the treatment of stroke. Unfortunately, fingolimod has poor solubility and very extensive partitioning to plasma proteins and RBCs (in whole blood, 86% partitions to RBCs, 13.96% to plasma proteins, and 0.04% is free). We develop a liposomal formulation that slows the partitioning of fingolimod to RBCs and plasma proteins, enables intravenous delivery, and additionally prevents fingolimod toxicity to RBCs. The liposomal formulation nearly completely prevented fingolimod adsorption to plasma proteins (association with plasma proteins was 98.4 ± 0.4% for the free drug vs. 5.6 ± 0.4% for liposome-loaded drug). When incubated with whole blood in vitro, the liposomal formulation greatly slowed partitioning of fingolimod to RBCs and also eliminated deleterious effects of fingolimod on RBC rigidity, morphology, and hemolysis. In vivo, the liposomal formulation delayed fingolimod partitioning to RBCs for over 30 min, a critical time window for stroke. Fingolimod-loaded liposomes showed improved efficacy in a mouse model of post-stroke neuroinflammation, completely sealing the leaky blood-brain barrier (114 ± 11.5% reduction in albumin leak into the brain for targeted liposomes vs. 38 ± 16.5% reduction for free drug). This effect was only seen for liposomes modified with antibodies to enable targeted delivery to the site of action, and not in unmodified, long-circulating liposomes. Thus, loading fingolimod into liposomes prevented partitioning to RBCs and associated toxicities and enabled targeted delivery. This paradigm can be used for tuning the blood distribution of small molecule drugs for the treatment of acute illnesses requiring rapid pharmacologic intervention.

Molecular profile of bladder cancer progression to clinically aggressive subtypes.

Bladder cancer is a histologically and clinically heterogenous disease. Most bladder cancers are urothelial carcinomas, which frequently develop distinct histological subtypes. Several urothelial carcinoma histological subtypes, such as micropapillary, plasmacytoid, small-cell carcinoma and sarcomatoid, show highly aggressive behaviour and pose unique challenges in diagnosis and treatment. Comprehensive genomic characterizations of the urothelial carcinoma subtypes have revealed that they probably arise from a precursor subset of conventional urothelial carcinomas that belong to different molecular subtypes - micropapillary and plasmacytoid subtypes develop along the luminal pathway, whereas small-cell and sarcomatoid subtypes evolve along the basal pathway. The subtypes exhibit distinct genomic alterations, but in most cases their biological properties seem to be primarily determined by specific gene expression profiles, including epithelial-mesenchymal transition, urothelial-to-neural lineage plasticity, and immune infiltration with distinct upregulation of immune regulatory genes. These breakthrough studies have transformed our view of bladder cancer histological subtype biology, generated new hypotheses for therapy and chemoresistance, and facilitated the discovery of new therapeutic targets.

Automated measurement of distance-walked as a "sixth vital sign" for detecting infusion reactions during preclinical testing.

Infusion reactions are a major risk for advanced therapeutics (e.g., engineered proteins nanoparticles, etc.), which can trigger the complement cascade, anaphylaxis, and other life-threatening immune responses. However, during the early phases of development, it is uncommon to assess for infusion reactions, given the labor involved in measuring multiple physiological parameters in rodents. Therefore, we sought to develop an automated quantification of rodent locomotion to serve as a sensitive screening tool for infusion reactions, with minimal added labor-time for each experiment. Here we present the detailed methods for building a motion tracking cage for mice, requiring ∼$100 of materials, ∼2 h to build and set up completely, and employing freely available software (DeepLabCut). The distance-walked after injection was first shown to have the predicted effects for stimulants (caffeine), sedatives (ketamine), and toxins (lipopolysaccharide). Additionally, the distance-walked more sensitively detected the effects of these compounds than did pulse oximetry-based measurements of the classical vital signs of heart rate, respiratory rate, and blood oxygen saturation. Finally, we examined a nanomedicine formulation that has been in preclinical development, liposomes targeted to the cell adhesion molecule ICAM. While this formulation has been studied across dozens of publications, it has not previously been noted to produce an infusion reaction. However, the automated motion tracking cage showed that ICAM-liposomes markedly reduce the distance-walked, which we confirmed by measuring the other vital signs. Importantly, the motion tracking cage added < 5 min of labor time per 5-mouse condition, while pulse oximetry with a neck cuff (by far the most stable oximetry signal in mice) required âˆ¼ 100 min of labor time. Thus, automated measurement of distance-walked can indeed serve as a "sixth vital sign" for detecting infusion reactions during preclinical testing. Additionally, the device to measure distance-walked is easy and cheap to build and requires negligible labor time for each experiment, enabling distance-walked to be recorded in nearly every infusion experiment.

Mechanisms by Which Liposomes Improve Inhaled Drug Delivery for Alveolar Diseases.

Diseases of the pulmonary alveolus, such as pulmonary fibrosis, are leading causes of morbidity and mortality, but exceedingly few drugs are developed for them. A major reason for this gap is that after inhalation, drugs are quickly whisked away from alveoli due to their high perfusion. To solve this problem, the mechanisms by which nano-scale drug carriers dramatically improve lung pharmacokinetics using an inhalable liposome formulation containing nintedanib, an antifibrotic for pulmonary fibrosis, are studied. Direct instillation of liposomes in murine lung increases nintedanib's total lung delivery over time by 8000-fold and lung half life by tenfold, compared to oral nintedanib. Counterintuitively, it is shown that pulmonary surfactant neither lyses nor aggregates the liposomes. Instead, each lung compartment (alveolar fluid, alveolar leukocytes, and parenchyma) elutes liposomes over 24 h, likely serving as "drug depots." After deposition in the surfactant layer, liposomes are transferred over 3-6 h to alveolar leukocytes (which take up a surprisingly minor 1-5% of total lung dose instilled) in a nonsaturable fashion. Further, all cell layers of the lung parenchyma take up liposomes. These and other mechanisms elucidated here should guide engineering of future inhaled nanomedicine for alveolar diseases.

Meta-analysis of material properties influencing nanoparticle plasma pharmacokinetics.

Thorough characterization of the plasma pharmacokinetics (PK) is a critical step in clinical development of novel therapeutics and is routinely performed for small molecules and biologics. However, there is a paucity of even basic characterization of PK for nanoparticle-based drug delivery systems. This has led to untested generalizations about how nanoparticle properties govern PK. Here, we present a meta-analysis of 100 nanoparticle formulations following IV administration in mice to identify any correlations between four PK parameters derived by non-compartmental analysis (NCA) and four cardinal properties of nanoparticles: PEGylation, zeta potential, size, and material. There was a statistically significant difference between the PK of particles stratified by nanoparticle properties. However, single linear regression between these properties and PK parameters showed poor predictability (r2 < 0.10 for all analyses), while multivariate regressions showed improved predictability (r2 > 0.38, except for t1/2). This suggests that no single nanoparticle property alone is even moderately predictive of PK, while the combination of multiple nanoparticle features does provide moderate predictive power. Improved reporting of nanoparticle properties will enable more accurate comparison between nanoformulations and will enhance our ability to predict in vivo behavior and design optimal nanoparticles.

Pre-clinical investigation of astatine-211-parthanatine for high-risk neuroblastoma.

Astatine-211-parthanatine ([211At]PTT) is an alpha-emitting radiopharmaceutical therapeutic that targets poly(adenosine-diphosphate-ribose) polymerase 1 (PARP1) in cancer cells. High-risk neuroblastomas exhibit among the highest PARP1 expression across solid tumors. In this study, we evaluated the efficacy of [211At]PTT using 11 patient-derived xenograft (PDX) mouse models of high-risk neuroblastoma, and assessed hematological and marrow toxicity in a CB57/BL6 healthy mouse model. We observed broad efficacy in PDX models treated with [211At]PTT at the maximum tolerated dose (MTD 36 MBq/kg/fraction x4) administered as a fractionated regimen. For the MTD, complete tumor response was observed in 81.8% (18 of 22) of tumors and the median event free survival was 72 days with 30% (6/20) of mice showing no measurable tumor >95 days. Reversible hematological and marrow toxicity was observed 72 hours post-treatment at the MTD, however full recovery was evident by 4 weeks post-therapy. These data support clinical development of [211At]PTT for high-risk neuroblastoma.

Distinct Gene Mutations Are Associated With Clinicopathologic Features in Urachal Carcinoma.

OBJECTIVES: To investigate the gene mutational profile of urachal carcinoma in correlation with its clinicopathologic features. METHODS: We analyzed genetic mutations in 30 cases of urachal carcinoma by next-generation sequencing (NGS) test. Histologic slides and clinical data were reviewed. RESULTS: The patients included 21 men and 9 women, with a mean age of 53 years (range, 24-75 years). The urachal carcinomas included mucinous (11), enteric (10), signet ring cell (8), and high-grade neuroendocrine (1) subtypes. Targeted NGS analysis demonstrated genetic mutations in all the urachal tumors (mean, 2; range, 1-4). TP53 was the most mutated gene (25), followed by KRAS (9) and GNAS (8) genes. TP53 mutations were more common in the signet ring cell subtype (7/8), and GNAS mutations were present only in the mucinous (5/11) and signet ring cell subtypes (3/8) but not in the enteric subtype (0/10). KRAS mutations were significantly associated with cancer stage IV (P = .02) and younger patient age (P = .046). Furthermore, the presence of KRAS mutations in urachal carcinoma portended a poorer overall survival (P = .006). CONCLUSIONS: Urachal carcinoma demonstrates frequent gene mutations that are associated with distinct clinicopathologic features. Gene mutation may underlie the development and progression of this aggressive disease.

Combating Complement's Deleterious Effects on Nanomedicine by Conjugating Complement Regulatory Proteins to Nanoparticles.

Complement opsonization is among the biggest challenges facing nanomedicine. Nearly instantly after injection into blood, nanoparticles are opsonized by the complement protein C3, leading to clearance by phagocytes, fouling of targeting moieties, and release of anaphylatoxins. While surface polymers such as poly(ethylene glycol) (PEG) partially decrease complement opsonization, most nanoparticles still suffer from extensive complement opsonization, especially when linked to targeting moieties. To ameliorate the deleterious effects of complement, two of mammals' natural regulators of complement activation (RCAs), Factors H and I, are here conjugated to the surface of nanoparticles. In vitro, Factor H or I conjugation to PEG-coated nanoparticles decrease their C3 opsonization, and markedly reduce nanoparticle uptake by phagocytes. In an in vivo mouse model of sepsis-induced lung injury, Factor I conjugation abrogates nanoparticle uptake by intravascular phagocytes in the lungs, allowing the blood concentration of the nanoparticle to remain elevated much longer. For nanoparticles targeted to the lung's endothelium by conjugation to anti-ICAM antibodies, Factor I conjugation shifts the cell-type distribution away from phagocytes and toward endothelial cells. Finally, Factor I conjugation abrogates the severe anaphylactoid responses common to many nanoparticles, preventing systemic capillary leak and preserving blood flow to visceral organs and the brain. Thus, conjugation of RCAs, like Factor I, to nanoparticles is likely to help in nanomedicine's long battle against complement, improving several key parameters critical for clinical success.

Supramolecular arrangement of protein in nanoparticle structures predicts nanoparticle tropism for neutrophils in acute lung inflammation.

This study shows that the supramolecular arrangement of proteins in nanoparticle structures predicts nanoparticle accumulation in neutrophils in acute lung inflammation (ALI). We observed homing to inflamed lungs for a variety of nanoparticles with agglutinated protein (NAPs), defined by arrangement of protein in or on the nanoparticles via hydrophobic interactions, crosslinking and electrostatic interactions. Nanoparticles with symmetric protein arrangement (for example, viral capsids) had no selectivity for inflamed lungs. Flow cytometry and immunohistochemistry showed NAPs have tropism for pulmonary neutrophils. Protein-conjugated liposomes were engineered to recapitulate NAP tropism for pulmonary neutrophils. NAP uptake in neutrophils was shown to depend on complement opsonization. We demonstrate diagnostic imaging of ALI with NAPs; show NAP tropism for inflamed human donor lungs; and show that NAPs can remediate pulmonary oedema in ALI. This work demonstrates that structure-dependent tropism for neutrophils drives NAPs to inflamed lungs and shows NAPs can detect and treat ALI.

Sarcomatoid Mesothelioma: A Clinicopathological and Immunohistochemical Study of 64 Cases.

Sixty-four cases of sarcomatoid pleural mesothelioma represent the basis of this study. The patients are 51 men and 13 women between the ages of 42 and 79 years, who presented with symptoms of chest pain, cough, and weight loss. Diagnostic imaging showed the presence of diffuse pleural thickening with encasement of the lung parenchyma in all the cases. All patients had surgical resection via extrapleural pneumonectomy. By immunohistochemistry, all cases were positive for cytokeratin AE1/AE3; however, reactivity with other markers including keratin 5/6, calretinin, and D2-40 was seen in different proportions, whereas a few cases showed positive staining for GATA3, WT1, and p40. All tumors were negative for carcinomatous epitopes (carcinoembryonic antigen, CD15, and TTF1). Our findings show that even though the use of immunohistochemical stains plays an important role in the final interpretation, the best results are accomplished by a global interpretation of clinical, radiographical, and immunohistochemical findings. It is also important to highlight that it does not seem to be a single immunohistochemical stain that is pathognomonic of sarcomatoid mesothelioma and that some other stains that are commonly used for other tumors may also show positive staining in a small percentage of sarcomatoid mesotheliomas.

Immunohistochemical Loss of DPC4 in Tumors With Mucinous Differentiation Arising in or Involving the Gynecologic Tract.

DPC4 immunohistochemistry (IHC) is usually part of the work-up of mucinous neoplasms in the ovary where the distinction between an ovarian primary and metastatic pancreaticobiliary adenocarcinoma (PanACa) must be made. Although DPC4 IHC is lost in about 55% (46%-61%) of PanACas and typically retained in most primary ovarian mucinous neoplasms, no study has evaluated the expression of this marker in a large cohort of neoplasms arising in or involving gynecologic (GYN) organs. In this study, we retrospectively analyzed the expression of DPC4 IHC in a total of 251 tumors and lesions related to the GYN tract in which DPC4 IHC stain was performed during the initial pathology evaluation. Of these, 138 were primary GYN tumors and lesions, 31 were metastatic GYN tumors involving non-GYN sites, and 83 were metastatic non-GYN tumors involving the GYN tract. We identified 27 cases with loss of DPC4 IHC expression of which 20 cases met the inclusion criteria (i.e. clinical information was available to determine the site of tumor origin). We observed that loss of DPC4 nuclear expression was most commonly seen in tumors of endocervical origin (n=7), of which 5 were gastric-type cervical adenocarcinomas (GCxACa) and 2 were usual-type cervical adenocarcinomas, either primary or metastatic. This was followed by tumors of the pancreaticobiliary tract (n=5), ovary (n=2), and appendix (n=1). In addition, 1 gastric-type vaginal adenocarcinoma (GVaACa) also showed loss of DPC4. Our findings indicate that in female patients with mucinous neoplasms involving the ovary or other sites, with loss of DPC4 by IHC, and negative pancreaticobiliary imaging, the possibility of an occult GCx/GVaACa, and rarely an ovarian primary must be considered.

Genome-wide Association Analysis Across 16,956 Patients Identifies a Novel Genetic Association Between BMP6, NIPAL1, CNGA1 and Spondylosis.

STUDY DESIGN: A case-control genome-wide association study (GWAS) on spondylosis. OBJECTIVE: Leveraging Geisinger's MyCode initiative's multimodal dataset, we aimed to identify genetic associations with degenerative spine disease. SUMMARY OF BACKGROUND DATA: Degenerative spine conditions are a leading cause of global disability; however, the genetic underpinnings of these conditions remain under-investigated. Previous studies using candidate-gene approach suggest a genetic risk for degenerative spine conditions, but large-scale GWASs are lacking. METHODS: We identified 4434 patients with a diagnosis of spondylosis using ICD diagnosis codes with genotype data available. We identified a population-based control of 12,522 patients who did not have any diagnosis for osteoarthritis. A linear-mix, additive genetic model was employed to perform the genetic association tests adjusting for age, sex, and genetic principal components to account for the population structure and relatedness. Gene-based association tests were performed and heritability and genetic correlations with other traits were investigated. RESULTS: We identified a genome-wide significant locus at rs12190551 (odds ratio = 1.034, 95% confidence interval 1.022-1.046, P = 8.5 × 10-9, minor allele frequency = 36.9%) located in the intron of BMP6. Additionally, NIPAL1 and CNGA1 achieved Bonferroni significance in the gene-based association tests. The estimated heritability was 7.19%. Furthermore, significant genetic correlations with pain, depression, lumbar spine bone mineral density, and osteoarthritis were identified. CONCLUSION: We demonstrated the use of a massive database of genotypes combined with electronic health record data to identify a novel and significant association spondylosis. We also identified significant genetic correlations with pain, depression, bone mineral density, and osteoarthritis, suggesting shared genetic etiology and molecular pathways with these phenotypes.Level of Evidence: N/A.

Typical and Atypical Carcinoid Tumors of the Mediastinum: A Biomarker Analysis of 27 Cases With Clinical Correlation.

Thymic typical and atypical carcinoids are rare and appear to be more aggressive than similar tumors in other sites. We retrospectively analyzed a group of biomarkers that hold therapeutic and prognostic utility, in 27 of these tumors. All cases were immunohistochemically stained with PAX5, MET, CRMP5, paxillin, p21, p27, EZH2, PDL-1, and Ki-67, and then H-scored. Clinicopathologic and survival data were statistically analyzed against staining (χ2 test). Five- and 10-year-survival rates were 53% and 18%, respectively. Mitotic counts ≥4 per 2 mm2 and tumor size ≥5 cm, associated with death of disease (DoD; P = .010 and .016). Ki-67 expression ≥1% associated with DoD (P = .003) and death within 5 years (P = .031). Biomarkers stained tumor cases as follows: PDL-1 = 0%, PAX-5 = 0%, MET = 7.4%, paxillin = 41%, CRMP5 = 78%, p21 = 63%, p27 = 63%, EZH2 = 37%, and MASH1 = 59%. Overall ± staining did not associate with survival or grade. Cases with low CRMP5 H-scores (<80) associated with DoD (P = .002), while CRMP5 H-scores >80 associated with 10-year survival (P = .022). Cases with high MASH1 H-score (>100) associated with DoD (P = .021). Accurate grading and staging remain paramount in predicting clinical outcome. Biomarkers may have significance in subsets of patients and the use of these studies likely should be focused on a more personalize type of approach.

Sarcomatoid Mesothelioma: A CDKN2A molecular analysis of 53 cases with immunohistochemical correlation with BAP1.

Fifty-three cases of sarcomatoid pleural mesothelioma were evaluated for CDKN2A (p16) homozygous deletion and correlated with BRCA-associated protein-1 (BAP1) expression by immunohistochemistry. The patients are 45 men and 8 women between the ages of 37 and 79 years (average age: 58 years), who presented with symptoms of chest pain, cough, and weight loss. Diagnostic imaging showed the presence of diffuse pleural thickening with encasement of the lung parenchyma in all the cases. All patients were surgically treated with extrapleural pneumonectomy. Loss of BAP1 reactivity was seen in 49 tumors and p16 homozygous deletion was seen in 41 tumors, while in 16 patients either BAP1 or p16 were noncontributory to the diagnosis of mesothelioma. However, we were able to detect a better survival rate in those patients in whom BAP1 was lost and p16 showed homozygous deletion. Our findings showed that even though the use of BAP1 and p16 are important tools in the diagnosis of mesothelioma, a proportion of cases still remains negative with approximately 30 % of the cases in which the concordance of BAP1 loss and p16 homozygous deletion will not be present. We consider that the final diagnosis of mesothelioma is best accomplished by a global interpretation of clinical, radiographic, and pathological features including immunohistochemistry and molecular studies.

Mucous Gland Adenoma: The Spectrum of Growth Patterns and the Diagnostic Challenges.

Mucous gland adenomas represent a small percentage of primary lung neoplasms. The accurate diagnosis of these benign tumors can be challenging not only on resected specimens but also more challenging in small bronchoscopic biopsies. If to that problem we add the issue that these tumors may also exist in the periphery of the lung, then it is easy to conclude that there is much difficulty in properly diagnosing these tumors with a core needle biopsy. Furthermore, there is little knowledge on the immunohistochemical properties and radiologic features of these tumors. Therefore, pathologists need to be aware of the spectrum of histopathologic features in these tumors and place them in perspective regarding the proper radiologic and immunohistochemical correlations. Needless to say, mucous gland adenomas exhibit a gamut of histopathologic features that can be easily confused with other more common tumor of the lung. Therefore, awareness of such features become essential in a benign tumor that is essentially diagnosed on morphologic grounds.

Diabetes mellitus type 2 is associated with increased tumor expression of programmed death-ligand 1 (PD-L1) in surgically resected non-small cell lung cancer-A matched case-control study.

OBJECTIVES: Programmed death-ligand 1 (PD-L1) expression is a biomarker for cancer immunotherapy. Diabetes mellitus type-2 is a comorbid disease associated with adverse outcomes in Non-Small Cell Lung Cancer (NSCLC). We aimed to investigate the differences in PD-L1 expression in diabetics. METHODS: A matched case-control cohort of surgically-resected NSCLC was assembled from an early multicenter study (PMID: 19152440). PD-L1 immunohistochemistry (Clone 22C3) was graded by a tumor positive score (TPS) system (TPS0: no staining; TPS1: <1%; TPS2: 1-49%; TPS3: ≥50%). Variables showing significance at univariate survival analysis were fit in a Cox regression survival model. RESULTS: Diabetics (n=40) and nondiabetics (n=39) showed no differences in age, gender, cancer stage, and follow-up. NSCLCs were more likely PD-L1 positive in diabetics but with tumor positivity <50% (TPS0: 7.5 vs. 20.5%, TPS1: 35 vs. 25.6%, TPS2: 45 vs.23.1%, TPS3: 12.5 vs. 30.8%, respectively; P<0.05). In diabetics, squamous cell carcinomas (SCC) and adenocarcinomas were mainly TPS2 (65% vs. 20%) and TPS1 (50% vs. 26%), respectively. Peritumoral inflammation correlated with TPS (r=0.228), a relationship accentuated in diabetics (r=0.377, P<0.05) but diminished and non-significant in nondiabetics (r=0.136, P≥0.05). This association was stronger in SCC (r=0.424). Diabetes was associated with increased tumor recurrence (HR: 3.08; 95%CI: 1.027-9.23). CONCLUSION: Diabetes is associated with an increase in peritumoral inflammation, PD-L1 positivity, and recurrence in NSCLC, more pronounced in SCC, suggesting the possibility of metabolic reprogramming and upregulation of PD-L1 by inducible pathways.

Cutaneous neoplasms composed of melanoma and carcinoma: A rare but important diagnostic pitfall and review of the literature.

We report two cases of combined cutaneous tumors composed of melanoma and carcinoma. The first tumor presented as a 5-mm pink-blue macule over the right zygomatic arch in an 85-year-old man. Shave biopsy and immunohistochemical studies revealed that the tumor was composed of melanoma (highlighted by SOX10 and MART-1, with high Ki-67 proliferative index) intermixed with nodular basal cell carcinoma (highlighted by pan-cytokeratin and Ber-EP4). The neoplastic melanocytes were confined to the basal cell carcinoma nodules, and a diagnosis of combined melanoma in situ and basal cell carcinoma was rendered. After therapeutic excision, the patient was disease-free at 9 months after the initial diagnosis. The second tumor presented as a 6-mm pink-brown crusted papule on the right forehead in an 89-year-old man. Shave biopsy and immunohistochemical studies revealed that the tumor was composed of malignant melanoma (MM) (highlighted by S100 and MART-1) intermixed with squamous cell carcinoma (SCC) (highlighted by cytokeratin and p63), and a diagnosis of combined MM-SCC was rendered. These two cases highlight the importance of recognizing these rare types of melanocytic-epithelial cutaneous neoplasms to arrive at an accurate diagnosis that may inform appropriate disease stage and therapy.

Clinicopathologic features of Buschke-Löwenstein tumor: a multi-institutional analysis of 38 cases.

Buschke-Löwenstein tumor (BLT) is a rare sexually transmitted disease, mostly described in clinical literature as case reports or small series. Here, we investigated the clinicopathologic features of BLT in a total of 38 cases retrieved from multiple academic institutions. The average age was 47.6 ± 12.8 (mean ± SD) years old at diagnosis. The male to female ratio was 4.4:1. Common presenting symptoms were pain/discomfort, bleeding, mass lesion, and discharge. It was frequently linked to smoking and positive human immunodeficiency virus status. The tumor size and thickness were 8.5 ± 6.6 cm and 1.5 ± 1.3 cm, respectively. Histologically, 19 (50%) cases had an invasive squamous cell carcinoma component and were associated with high-risk human papillomavirus infection. There was no lymphovascular or perineural invasion, or nodal metastasis at initial diagnosis. BLTs with invasion had higher frequency of dyskeratosis, neutrophilic microabscesses, and abnormal mitoses, but lower frequency of pushing border compared with BLTs without invasion. All patients underwent wide excision, and some also received chemoradiation therapy. After a median follow-up of 23 months (range 1-207), the recurrence rate was 23.7% and disease-specific mortality was 2.6%. In summary, we presented the largest case series of BLT to date to characterize its unique clinicopathologic features. Our study indicated that certain histologic features such as dyskeratosis, neutrophilic microabscess, and abnormal mitosis in the non-invasive portion may be important clues on lesional biopsy to predict the presence of underlying invasive carcinoma.

Primary mediastinal chondrosarcomas: do they really exist?

Chondrosarcomas primarily originating in the mediastinal compartment are vanishingly rare. Contrary to other unusual tumors of the mediastinum, chondrosarcomas have been described in either anterior or posterior mediastinum. The histopathological spectrum that has been described in these mediastinal tumors is similar to that described in soft tissues. In our current practice, diagnostic imaging plays an important role before any of these neoplasms is rendered as of mediastinal origin. It is also important to highlight that even though a tumor may be presenting as a mediastinal tumor, such information in essence does not constitute that the tumor is not in fact associated with another structure within the thoracic cavity, thus the importance of strict radiological correlation. Furthermore, molecular characterization of tumors that in the past were coded under the spectrum of chondrosarcomas, are now believed to represent different tumoral conditions, which raises important issues in tumor classification. Therefore, in this review, we will outline a more specific criteria regarding the diagnosis of chondrosarcomas, as wells as the essentials in the histopathological assessment of these tumors. In addition, we will discuss the current knowledge of these entities as well as their differential diagnosis, which inevitably will depend on the anatomic distribution of the tumor-anterior or posterior compartment.